Compensating gas cut-off



L. HILL cournnsmmc- GAS Cur-on May 3,1921. 1 1,626,609

Filed Feb. 14. 192 5 6 Sheets-Sheet I INVENTOR [nu/,5 H/u.

ATTORNEY COMPENSATING GAS CUT-OFF Fi led Feb. v14. 1925 -:s' Sheets-Sheet. 2

/% ''J.cs 1.15.; E:

lNVENTOR [00/5 11/11 May 3, 1927.

L. HILL COIIPENSATING GAS cur-or! Filed Feb. 14. 1925 is smu -shut 3 .lEURES 'LELTRE S ATTORNEY time required for the gas to be shut ofi, by action of the automatic mechanism-employedi Patented Mays, 1927. I

LOUIS HILL, or Anon; onto.

' 'ooivrPEnsA'rING ens cur-err.

Application filed February My invention relates to gas cutoff inecha nisms of the type used in connectlon'wlth gas stoves, for the purpose of enabling the flow of gas'to be cut off automatically in the event that the burner flame is extinguished under conditions .where the gas would otherwise be left flowing but without;

burning.

More particularly stated Iseekto produce a "compensating gas cutoff, so constructed and arranged 'asto reduce to, a minnnum the forthat purpose. In other words, I seek i anism of Figure 1, as this mechanism would be seen by an observer standing at the left,

i ca

to quicken the action of the automatic mechanism used for shutting off the gas supply.

Reference is made to the accompanying drawings forming a part of this specification',-and which like reference characters indicate like parts throughout the several figures.

Figure 1 is a fragmentary'front elevation showing oneform of my improved co'mpene sating gas cutoff as used upon a gasstove.

Figure 2 is a fragmentary plan of the same. I i

- Figure 3 is an elevation showing the mech- -of this figure. I c

Figure 4 is a fragmentary front elevation of the mechanism as it appears with the stoveheated and in action. i

Figure 5 is a'fragmentary :front "elevation showing another form ofmy improved compensating gas cut off.

Figure 6 is a section on the line 6 6 of Figure 5 looking inthe directionlof the arrow; Figure 7 is a section onthe line 77 of Figure 5 looking in the direction indicated by the arrow; 2 i I I will first describe the mechanism in Figures 1 to 4; inclusive. i c 'i The stove body is shown fragmentarily at 5, and'is provided with :a sheet metal wall 6 extendingvertically. 1

The burner tube'is shown at 7 and the burner holes atS. ,The burnertube' is pro vided witharose inlet head 9, and extending into this inlet head isa T head 10 for de livering' gas into the burnertube.

.A; gas pipe is shown at 11, and is con- 14, 1 925. SeriaINo. 9,186.

nected with the T head 10 for the purpose ofv supplying gas to the burner tube;

Air is admitted through-therose' head9..* alongwith the gas,-in the usual manner. c i

fThe gas pi e 11 is provided with a hand l'valve '12, carrying'a hand wheel 13 whereby this valve is actuated, I i I The gas pipe-11 is provided with another valvel, controlled under certain conditions as hereinafter described by action ofth'ermostatic mechanism for the'purpose of shut- 5 ting off the supply of gas to the burner. "The valve ltisf providedwith a revoluble plug 15, this' plug having mounted [upon it two arms16and17. The arm 16-servesas a handle for enabling the plug to be turned by hand, and the arm 17, though set by hand as hereinafter described,is released by action" of the thermostatic mechanism. .The arm 17 is in its action something like a trigger, and I therefore designate it as the trigger arm, A tensile spring 18 is connected with the valve plug 15 and with a fixedportionjof the valvejla. The spring is always :under tension, and its tendency is to turnfthe valve plug 15 in a counter-clockwise direction according to Figure 1.

The Media 16 and trigger arm, being fixed to the: valve plug 15, always occupy the same position relatively to this plug;

vlVith the handle- 16 and trigger arm 17 extending upwardly,"as indicated in full of gas-through the valve 14. WVith the handleil6land trigger arm 17 ,occupying'the positions indicated for, them by full lines in "lines in Figures. 1, 2 and 3, the valve plug is in such position as to prevent thei'flow Figure l, however, thevalve plug 15 is in such condition that gas passes freely through it and into the burner. i

The burner tube 7 is provided with a pair offlugs' 20'integral with it, andextending .through holesin these lugs is a shaft 21,

carrying a rocking arm 22. The shaft 21 has through the medium of this shaft the rocking arm 22-is journaled upon the lugs 20, and free to rock slightly, as indicated by full and broken lines in Figure 3. The rocking arm 22 is provided with 'a lug 22, in tegral with it and having the form indicated in Figure 3. This lug co-operates with the trigger arm 17', and holds 'the latter in the the forinindicatedfor it in Figure 2 and position indicated for it in Figure l while the stove is in action, as hereinafter described.

A spring 23 is connected with the rocking arm 22 and with the stove body. The tendency of this spring is to shift the arm 22 from the position indicated for it by full lines in Figure 8 to the position indicated for it by broken lines in that figure.

The arm 22 carries at its upper end a light thermostatic bar 24, so constructed and arranged that the upper end of this thermostatic bar is moved to the right according to Figure at when the bar is heated, so that while the stove is in action, and therefore heated, the thermostatic bar-.24- occupies the position indicated for it by full lines in Figure t; and when the stove is not in action and is therefore cold, the thermostatic bar just mentioned occupies the position indicated for it by broken lines in this figure.

A heavy thermostatic bar appears at 25, and is supported upon a mounting 26. The thermostatic bar 2:7 has the general "form of an inverted L; or in other words, has its upper end bent to the left accordingto Figure 4. Because the thermostatic bar 28 is more massive than the thermostatic bar 2 1 it. is relatively sluggish in its response to changes in ten'iperature. The net result is that the thermostatic bar 2 1 moves more quickly in response to changes or" temperature and has a wider range of movement than the thermostatic bar 25;

Thetwo thermostatic bars 2 1 and 25 are so proportioned, constructed and arranged that when the stove is idle and thus cold the bars occupy the respective positions in dicated t'or them by broken lines in Figure at, but when the stove is in action and thus heated the bars appear as indicated by full lines in this figure.

Vith the stove cold and the thermostatic bars 24 and 25 occupying the positions indicated for them by full lines in Figure 4t, the thermostatic bar 2,1- is not in engagement with the thermostatic bar 25 and can thcretore be moved treely past the same by roclo ing the arm 22; When, however. the bars are heated and occupy the positions. indicated for them by full lines in Figure 41, the bar2t is lodged against the adjacent portion ot the bar 23, the rocking arm 22 being; thereby locked and prevented from rocking under tension ot the spring With the various movable parts occupying the relative positions indicated for them by full lines by Figure 3, the operator grasps thehandle 16 and turns the same in a clockwise direction, so as to rock the ping; 15 and bring the handle 16 and trigger arm 17 into the; positions indicated for them by full lines in Figure 4. The downward movement of the trigger arm 17 causes this arm to engage and pass by the center of the lug 22 carried by the rocking arm Thus virtually this lug acts as a cam for actuating}; the arm 22 and parts carried by it, in order to allow the arm 17 to pass. As soon as the arm 17 is below the center of the lug 22, however, the rocking arm 22 may resume the position indicated for it by full lines in F igure 4. ith the moval'ile parts in the position thus contemplated, the lug: 22 will now hold down the arm 1?, and thus prevent the valve plug 15 from turning in responseto the tension of the spring 18, provided the thermostatic bars 2 1 and are heated by the stove; or in other words provided the thermostatic bars 24; and 25 occupy the positions indicated for them by full lines in A lQ'lllG 1. This leaves the IOtliing arm 22 locked in position, and it so r mains while the stove remains heated. It for any reason, however, the thermostatic bars 2 1 and 25 cool off, as for instance it the gas flame be extinguished by a sudden gust of wind, the thermostatic bar 2% shitts its upper end and is thus released from its engagement with the thermostatic bar 25, and now rocks slightly in a counter-clock wise direction according to Figure 3, so as to allow the trigger arm 17, under tension of the spring 18, to pass upwardly and glide over the adjacent curved surface of the 22 The tension of the spring 18 thereupon causes the valve plug 15 to turn, and cut off the supply of The operation of the form of my device appearing in Figures 1 to rinclusive may be readily understood from the "foregoing description.

With the stove cold the parts. normally occupy the positions indicated tor them in Figures 1 and 2. Suppose that with the parts in these posit ons the stove is to be lighted.

The operator grasps the hand wheel 13, and by turning it opens the valve 12. The

Vegas passes up the gas pipe and through the valve 141-, now open, and through the '1' head 10 into the burner tube 7. so as to escape from the openings 8. The operator by applying; a lighted match to the gas escap inn; from these openings lights the stove. The heatof the stove causes both of the thermostatic bars 24 and 25 to bend, but the bar 24 bends more rapidly and swings to a greater distance than the bar 25, so that the that the valve 14 is open. The handledfi being releasedythe movable partslremam 1n the position they now occupy, and this con; tinues as long as the gas fia1ne=cont1nues to burn. i

w Suppose, next, vthat in consequence of a sudden gust of wind orrthe like the gas flame Yis'blown out and the stove cooled'off. -The shownxin Fi,9;ures 5, 6 and 7. v 3 Instead of the rock ng arm 22 above de- ;SCI'1bed,I use a rocklng arm 27-which carries thermostatic bar 24 quickly straightens out,

and the thermostatic bar .25 makes a' movement toward resuming its normal posltlon, thus travelmg 1n the same directlon as the portion of the thermostatic bar 24 with 'which it is in engagement. However, the rthern' ostaticbar 24: travels 'more' rapidly thanxthebar 25 and quickly outstrlps the latter, so that the bar 24 is released from its engagement with the bar 25; This enablesthe rocking arm 22, now under control *ofqthe-lug 22 acting as a cam, to rock slight- 1 ly againstthe tension of the spring 23, and

by (so-doing to release'the trigger arm217.

This allows the various movable parts to resume the positions normal to them when the stove is cold. The movement above described for the valve plug v causes the valve 14 to close and shut off the supply of gas.

It will be noted that the thermostatic I bars24 and whenactua-ted by changes of temperature, always move in thesame direction, butat unequal speeds, the travel of the bar 24being; always greater than that of the bar25. By this arrangement the bar' 24 is allowed considerable play: and the r travel. of the bar 25 reduces thedistance otherwise necessary to betraveled: by the bar 24in order-to enable it to'control the gas supply as above described. This reductionflin. the distance traveled by'the bar 24 is an important point, as it'enables the automatic action of the valve llEtO be quickened considerably,and this is in the line ofs'afetyr Moreover by having both of the thermostatic bars 24 and. 25 curved considerably, to the right accordingto Figure 4 in consequence of theheat of thestove, and by giving the bar 24 arelativelywide range of movement accordingly, the chances for failure of the bar 24 to disengage itself from the bar 25 at the proper time are greatlvdiminished.

I will now describe the form of my device at its upper end a thermostatic bar 28. The rocking arm 27 as'a wholeis mountedupon a shaft '29 which extends through. lugs. 20,

as above described with reference to the "shaft 21 shown in Figuresl to 4 inclusive.

Near the lower edge of the sheetmetal wall. 6 and, supported upon the wall is a ,plate30, which acts as a limitingstop for the arm 17 whenthe latter is turned, as may be understood from Flgure 5;

Connected with the T head is a pipe Q31 and 3'7 are inengagement.

*scription. v

indicated "in Figure 5.

' wind the flames of the stove are extinguished, ,so that gas continues to flow; When this and extending throughthis pipe is a copper wire 3 2which does notquite fill it,'and thus "leaves 'alittle room for the gas to pass upwvardly through the pipe 31; These parts are so proportioned and arranged that when" the stove is not in action, and consequently is cold, there is more room betweenthepipe 31 and the wire 32 within than'when the stove is in action and consequently is heated. The idea isthat the expansion of the-copper uwire 32 restricts the opening of annular form between the wire32 and the pipe'31, and in doing this limits the carrying capacity of the pipe 31. 1 i a -Located upon the wall 6 and adjacent the it thermostatiobar 28 isa block 36, carrying a shortand thick thermostatic bar 37 having the form indicated in Figures'5 and 6. by The Y thermostatic bar 37 has substantially the form of an inverted Lan'd'isprovided with a notch 38 and wit-h asloping edge 39as indicated more particularly iii-37. a

The purpose of the sloping edge is to en able the thermostatic bar 28 to engage rather "firmly the thermostatic bar 37 and to pref the position indicated 'forit in Figures 5 and 7.y.Tl1at is to say the tension of the spring 18 tends to cause the arm 17 toswing I upwardly, but thisflupward swing is for the time being retardedbv the lug, 27 as niay be understood froInflFigure 7 i ,Theoperation of the form of my device appearing in Figures 5, 6 and 7 may be readily understood from the foregoing de- 'The gas being turned: 34 and 35 are lighted.

The operator grasping thearm 16 turns it, clockwise until itbecomes horizontal as In doing this the rocking 'arm 27 swings'slightly so asto on, s the pilot flames enable the arm 27 to pass below the lug 27? as indicated in Figure 7.' The operator holds the arm 16 in horizontal positionuntil after the gas is lighted and burning freely,

arm 17down, when this arm is brought into so that the thermostatic bar 28 becomes heated and its upper end bends to'the right. This brings the thermostaticbar 28 into en-.

7 gagement with the thermostatic bar 37. The ,rocklng arm 37 is now unableto rock, because held from so doing by" thefthermostatic bar 37. The parts remain in the positions theynow occupy so longas the stove continues to burn;

- Suppose, next, that by a sudden-gust 10f happens the cooling of the thermostatic bar 28 tends to cause this bar to straighten out. and in so doing, to disengage itself from the thermostatic bar 37'. However, the sloping of 39 slightly retards its movements and keeps the thermostatic bar 38 in rather close engagement with the thermostatic bar 37 for a moment. However, the thermostatic bar 28 is quickly released from the sloping edge and swings to the left or in a counterclockwise direction according to Figure 5. As soon as the thermostatic bar 28 is thus released, the rocking arm 27 is thereby rendered free to rock. Hence the upward pressure of the arm 17, under tension of the spring 18, causes the arm 17 to rise and by acting upon the lug 27 to rock the arm 27 back and forth within narrow limits. This movement of the rocking arm 27 is for the purpose of releasing the arm 16, and this arm being released the tension of the spring 18 closes the valve through which gas is supplied to the T head and thence to the stove.

Except as otherwise above described, the structure and action oi the mechanism shown in Figures 5, 6 and 7 is similar to that of the construction appearing in the other figures.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is as follows:

1. In a gas stove the combination of a gas burner, a gas pipe leading to said burner, a valve connected with said pipe for controlling the flow of gas through said pipe to said burner, a pair of thermostatic bars controllable by heat of the stove, one of said bars being more quickly responsive than the other to changes of temperature, said thermostatic bars being so positioned that they move into engagement with each other when subjected to uniformly high temperature, and move out of engagement with each other when the temperature of both bars is reduced, and mechanism connected with said valve and with one of said bars. and controllable by one of said bars after its disengagement trom the other bar, for the purpose of closing said valve.

2. In a gas stove the combination of a gas burner, a gas pipe leading to said burner, a valve connected with said pipe for control ling the flow of through said pipe to said burner, a trigger arm connected with said valve for opening said valve, a rocking arm provided with a portion for engaging said trigger arm in order to restrain said trigger arm and thus prevent said valve from closing, means for closing said valve whenever said trigger arm is released, a thermostatic bar carried by said rocking arm and movable therewith, and a thermostatic bar disposed adjacent said first mentioned thermostatic bar and fixed in position, said second mentioned thermostatic bar being but when both of said thermostatic bars are cooled, said first mentioned thermostatic bar moves out of engagement with said second mentioned thermostatic bar and thus releases said trigger ar 8. In a gas stove the combination of a gas burner, a gas pipe leading to said burner, a valve connected with said pipe for controlling the flow of gas from said pipe to said burner, a trigger arm connected with said valve for opening said valve and temporarily keeping it open, a rocking arm disposed adjacent said trigger arm and provided with a portion for engaging said trigger arm in order to hold said trigger arm and thus prevent said valve from closing, a thermostatic bar carried by said rocking arm, another thermostatic bar disposed adjacent the path of travel of said first mentioned thermostatic bar, the thermostatic bars being so formed and arranged that they may lock together when both are subjected to a uniformly high temperature, thus preventing said rocking arm from releasing said trigger arm, said thermostatic bars being unequally sluggish in response to changes of temperature, and so arranged that they disconnect from each other when both arms are subjected to a drop in temperature.

4. In a gas stove the combination of a thermostatic bar having a general fixed position but movable in response to changes in temperature, said theri'nostatic bar being massive in construction and sluggish in its thermostatic action, another thermostatic bar movable bodily in relation to said first mentioned thermostatic bar and also movable in response to its own ten'iperature, said second mentioned thermostatic bar being movable more quickly than said first mentioned thermostatic bar as regards changes of ten'lperature, means for heating both of said thermostatic bars, a gas supply, and mechanism releasably held by said thermostatic bars and controllable by a dili'erential action thereof for shutting ofi' said gas supply.

5. In a gas stove the combination of a pair of thermostatic members so positioned and arranged so as to be heated together by the general heat'of the stove, one or said ther mostatic members being more sluggish than the other in responding to changes in temperature, a gas pipe for supplying gas to the stove, a valve carried by said gas pipe for controlling the flow of gas to the stove, and mechanism connected with. said valve and controllable by differential movements of said thermostatic members for actuating said valve.

.6. In a gas stove the combination of a gas burner, a gas pipe leadingtosaid burner,

a valve connected With said gaspipe for:

controlling the flow of gas therethrough to said burner, a trigger arm connected to said valve for opening said valve and temporarily holdingit'open, a rocking arm provided With a portion for engaging said trigger arm in order to restrain said trigger arm T and thus'prevent Said. valve from closlng,

means forclosing said valve Whenever said trigger arm 18 released, and a second thermostatic bar disposed adjacent said first'mena tioned thermostatic bar and fixed in position.

7. In a gas stove the combination of a gas burner; a gas pipe leading to said gas burner, a valve connected With said gas pipe for controlling ,theflow of gas through said gas pipe to said gas burner, a trigger arm connected with said valve for opening said valve,'a rocking arm provided with a portion for engaging said trigger arm in order to restrain said trigger arm and thus prevent said valve from closing, means for closing said valve Whenever said trigger arm 1s released, a thermostatic bar mounted upon mit and State of Ohio, this sixthday of February, 1925. I e LOUIS HILL.

soi 

